shader: Require dual source blending

src/video_core/vulkan_common/vulkan_device.cpp

@@ -219,7 +219,7 @@ Device::Device(VkInstance instance_, vk::PhysicalDevice physical_, VkSurfaceKHR
             .geometryShader = true,
             .tessellationShader = true,
             .sampleRateShading = true,
-            .dualSrcBlend = false,
+            .dualSrcBlend = true,
             .logicOp = false,
             .multiDrawIndirect = false,
             .drawIndirectFirstInstance = false,
@@ -678,6 +678,7 @@ void Device::CheckSuitability(bool requires_swapchain) const {
         std::make_pair(features.geometryShader, "geometryShader"),
         std::make_pair(features.tessellationShader, "tessellationShader"),
         std::make_pair(features.sampleRateShading, "sampleRateShading"),
+        std::make_pair(features.dualSrcBlend, "dualSrcBlend"),
         std::make_pair(features.occlusionQueryPrecise, "occlusionQueryPrecise"),
         std::make_pair(features.fragmentStoresAndAtomics, "fragmentStoresAndAtomics"),
         std::make_pair(features.shaderImageGatherExtended, "shaderImageGatherExtended"),